Didymoglossum petersii, the dwarf bristle fern,[2] is a species in the family Hymenophyllaceae,[1] (filmy ferns).

It is one of three filmy ferns native to a significant area of the United States.

It is found only in the nine most southeastern states, south of the Kentucky/Virginia - Tennessee/North Carolina dividing line, as well as in Mexico and Guatemala.

[citation needed] The genus Didymoglossum is accepted in the Pteridophyte Phylogeny Group classification of 2016 (PPG I),[3] but not by some other sources.

As of October 2019[update], Plants of the World Online merged the genus into a broadly defined Trichomanes, treating this species as Trichomanes petersii.